Many hundreds of years ago when the well-known style of Irish dancing began in the country side of Ireland, most houses of the poor - and that means most houses - only had a dirt floor which was not a lot of use for dancing on if you were holding a ceildh (pronounced kay-lee and meaning party - more or less). So in order to make the dancing easier the owners of the house which was holding the party would take the doors off their hinges and lay them on the floor. There was just enough room on each door for two people to dance, providing they did not fling their arms about - hence the original name for Irish dancing - Door Dancing.